In recent times, the proliferation of portable computing devices has revolutionized the world's computing environment. Fueled by advances in computing power and by the spread of high-speed wireless communications networks, this revolution is rapidly expanding both the number and the types of portable devices. Some portable devices, including personal digital assistants (PDAs) and cellular telephones, use modern computing and communications technology to provide enhanced versions of specific services. Other portables, such as laptop and hand-held computers, rival traditional, or “desktop,” computers in capability. (For the sake of brevity, the present discussion calls fixed-location personal computing devices “desktop computers.” This phrase is meant to include tower computers, centralized servers, and any other computing device that is not designed to move around.)
However, and despite some predictions, the emergence of portable computing has not led to the demise of the desktop computer. Desktops still often enjoy advantages in screen size, in wealth of peripheral devices, in speed of communications connections, and in price over portable devices. Because of this, most people with portable devices still use a fixed-location desktop computing device at home and at work.
People who use both portables and desktops have become accustomed to linking the devices together. This linking is performed in the service of “alternative” or “sequential” use. A portable is often used while commuting or on trips, while a desktop is used whenever the user is in the office or at home. When the user brings the portable to the location of the desktop computing device, the devices are temporarily linked together in order to synchronize their information content. For example, documents created on the portable are copied to the desktop for more reliable storage and to be printed on network printers. E-mails received at the desktop are transferred to the portable so that they may be read and answered when the user is on the move.
What has been lacking is a workable paradigm for using the portable and desktop computing devices concurrently. Once its data store is synchronized with the desktop, a wonderfully capable portable can sit unused until the time comes for another commute or business trip. In the eyes of corporate (and personal) accounting, this lack of concurrent usefulness makes the portable device an “additional” expense over and above the “necessary” expense of the desktop device.